Reserch On Hydration Reaction Of ?-Methylstyene

a,a-dimethyl benzyl alcohol(CA)as an important chemical raw materials,both as a spice can also be used as the production of hydrogen peroxide diisopropyl benzene raw materials,in the industrial application is very extensive.At present,the industrial production of CA process route for the use of reduced inorganic salt reduction of hydrogen peroxide cumene,but there are serious environmental pollution and poor economic problems in this process.Yanshan Petrochemical plant using hydrogen peroxide cumene to produce phenol in the process line will produce low value of industrial applications of the by-product ?-methyl styrene.At the starting point that in order to solve the problem of the production of CA in the old process and to convert the by-product a-methyl styrene which is a very low value of industrial application to CA with high industrial added value,this article is presented studying on Preparation of CA by Hydration of Ethylene.This project is the cooperation project between Beijing University of Chemical Technology and Yanshan Petrochemical Company,and combined with the actual situation of Yanshan Petrochemical Phenol Acetone Plant,the new process of a,a-dimethylbenzyl alcohol was developed.The reaction involved was a-styrene and water under the conditions of sulfuric acid hydration reaction,resulting in a,a-dimethyl benzyl alcohol.This topic mainly from the following three aspects:Under the condition of without organic fertilizer direct hydration,for different kinds of acidic catalyst screening,select the best performance of the catalyst.Direct hydration reaction lead ?-methyl styrene polymerization under acid environment problem,can reduce product selectivity.We proposed a method of surface active agent is added in the system for this inhibition between a-methyl styrene polymerization,through to the surfactant screening,which screening water-soluble polyethylene glycol-2000 as a surface active agent.By adding a small amount of surfactant can greatly improve the product selectivity,and through the production process to do optimization design,explore the optimal production technology.Direct hydration exist the problem of low conversion rate,the study found that main reason is that limit the conversion rate of the interphase mass transfer resistance.In order to decrease the mass transfer resistance,we put forward the method of adding organic solvent in the reaction system.Through the screening of different organic solvents,acetone as solvent,can greatly improve the reaction conversion rate and won't influence on the selectivity.Then we optimized the process conditions and through orthogonal design to find out the optimal process conditions.This topic is on the basis of technological characteristics to study the new method to produce alpha and a-dimethyl benzyl alcohol.Combined with its technological characteristics,we put forward a new process route,and the reaction let stand for the oil and water two phase separation.Water cycled back to the reaction kettle.Then the oil phase put into the subsequent separation section to realize the separation of organic solvent and the product.Organic solvent and unreacted alpha methyl styrene cycle back to the reaction kettle for reuse,thus forming a closed loop,not external discharge of pollutants,to meet the requirements of the new technology on economy and environmental protection.On the bases of material and energy balance,we used the simulation software of Aspen Plus to simulate the operating process.Next we used the simulation data to design reactor and heat exchanger.Through refer to "chemical engineering design manual" and other professional design books,we choose the appropriate equipment.In additional,we use Auto CAD software to draw flow chart of the material,material flow chart with control points,workshop equipment level elevation layout and main technological conditions.